What were the biggest problems encountered?:
Documentation was lacking in key details and had a number of significant errors. In some places, it was difficult to understand. No supplied instrument drivers. Problems with obtaining technical support from B&K Precision despite numerous contacts and "promises".

Detailed Review:

B&K Precision BA6010 Battery Analyzer RoadTest Review

By Gough Lui - September 2018

Our modern, mobile lifestyle could not exist without the humble battery. An electrochemical device, it stores the power necessary to run the electronics we take for granted. Batteries have always been a fascinating subject for me as they are often an Achilles heel of mobile devices – I spend quite a bit of my own time testing them just out of curiosity just to see how they degrade over time and whether you’re really getting what you pay for. This was one of the reasons I was delighted to have been previously awarded a B&K Precision Model 8600 DC Electronic Load. This has been immensely helpful in characterising different batteries and power supplies but using a load to characterise batteries isn’t always appropriate as it is time consuming, causes wear on secondary batteries and permanently depletes primary batteries.

It is with thanks to element14 and B&K Precision that I am given the opportunity to review the B&K Precision BA6010 Battery Analyser. This device performs no-load characterisation of a battery’s internal resistance/capacitance through the use of 1khz AC injection in a manner similar to an LCR meter. This permits rapid screening and testing of cells as well as interconnections in a pack. While a battery analyser might be a fairly niche product that will appeal mostly to those who might have a battery manufacturing plant or be building, servicing or maintaining battery packs, I hope that this review will still be interesting and useful for a wider audience.

I will be putting it through my usual, comprehensive and onerous battery of tests to try and exercise every feature, using all the test equipment I’ve managed to amass along the way, while giving my honest opinion of the device. As I’ve been criticised in the past for delivering overly-long monolithic reviews, I’ve continued on in the same style as my previous RoadTest – only providing overview conclusions in this main review document with details provided in blog posting.

I hope that you can follow along, click through to some of the more detailed blogs for more information (and pyvisa scripts), leave comments/questions for me and like/rate/share the review if you feel it has been useful.

Market Survey

Batteries themselves are not “simple” ideal voltage sources. Battery analysis can be a rather confusing topic owing to the variety of test methods which produce incomparable results. When shopping for a battery analyser, it’s important to read the datasheet thoroughly so as to understand what your unit actually does, the values it can report, how these are derived and how they relate to the parameters you are interested in.

There are a number of ways in which batteries can be tested, including:

Open circuit voltage test – this is the simplest test and can be done rapidly with a multimeter. This can provide information about state of charge and whether the cell has completely failed, but cannot provide information about the capacity or power delivery capability of the cells. Accurate estimation can only be made from batteries with a significant “slope” in their voltage function and will be skewed if the battery is under load or recently taken off the charger (due to surface charge) and may be dependent on temperature.

Load testing – this involves discharging a battery under known load and timing the process to prove the energy available from a battery. This is time consuming, loads required can be large or expensive, can involve taking the unit out of service, cannot be accurately performed while a battery is being charged or drawn from and it will consume cycle life from a battery. However, load tests are the only way to guarantee that the battery can deliver a given amount of charge at a set rate. By pulsing the load, it is possible to determine a “DC” internal resistance reading.

AC impedance / conductance testing – this involves injecting an AC signal of a fixed frequency into the battery and measuring the ripple developed at the terminals. This is convenient as it is fast, can be performed while the battery is in service and does not “damage” the battery or consume power from it. It provides some information as to the health of the battery (i.e. the impedance of the cells including interconnections) which can be charted over time to detect battery failure prematurely. However, it cannot be used to prove capacity (although some units may estimate battery capacity based on the readings, the accuracy is disputed). This is often used for production screening of batteries, with some vendors providing a guideline value on datasheets based on the 1khz AC method, however, these values often do not directly correspond to the DC internal resistance derived from pulsed load tests.

Electrochemical Impedance Spectroscopy (EIS) testing – this is a more sophisticated version of AC impedance testing which uses a number of frequencies instead of just one, in order to try and better characterise what is happening within the cell. This produces more data, but translating this into capacity and health seems to be a proprietary algorithm available from only a few select vendors with disputed accuracy.

Because of the variety of battery testing and analysis methodologies available, we focus on the market segment of battery analysers which employ 1khz AC based methods.

When it comes to the B&K Precision BA6010, it offers a very compelling package for the price. Compared with the more well-known brands, the analyser is very much cheaper than the competition while offering more measurement modes, better connectivity and a better display. While it is not portable, it does also offer quite competitive resistance accuracy. The only downside is that the voltage accuracy and resolution is not the best – however, it’s still better than a good slice of the competition for under half the price.

As the unit is a bit of a “niche” product, the main competition actually seems to originate from Chinese test equipment manufacturers. When even compared to these analysers, the BA6010 still offers close to the best specifications at a price only marginally more than you might get if you “risked” buying one from a shady shopping site, foregoing after-sales support, warranties or even assurance that the claimed accuracy levels can be achieved as it seems to vary from seller to seller for the same unit.

As a result, if you’re after a benchtop battery analyser that does voltage and 1khz AC resistance/impedance-based measurements, the B&K Precision BA6010 is actually a no-brainer choice. You’d likely spend at least twice as much to buy another reputable analyser, or save a few pennies buying an “unknown” but risk headaches further down the track.

Unboxing

The BA6010 comes packaged in a distinctively blue-and-white box which proudly shows its B&K Precision branding. The unit, Kelvin clip test fixture, EU power cable (220V) and limited documentation are packed within, along with instructions to obtain full documentation online. It was quite well packed and protected, surviving the journey to Australia.

The instrument has a gorgeously large matte-finish LCD screen which is glare-resistant, with soft-keys and more traditional keypad entry to the right. There is a USB-host connector for screenshot and data saving to USB memory and a pass-fail indicator. Connections are made using the centre-pin of BNC connectors to ensure quality connections.

The unit also sports a good variety of interfaces including USB host (USB CDC/USB TMC), RS-232C, remote trigger and handler interface. There is also a grounding point and fused IEC power inlet on the rear.

The Kelvin clip test fixture provided has a very flexible lead of an adequate length, with gold plated clips that have grooved surfaces for more reliable connections. Each side of the clips is labelled with its function and the clips even have soft-touch rubber handles.

As for downsides, it seems that my unit was shipped with the wrong calibration certificate and test report, possibly due to a one-off inspection mix-up as an early unit. Owing to its “early” nature, the calibration is believed to expire soon as well.

I would have liked to see a set of Kelvin probes with pogo-pin style contacts for other types of battery without flat terminals to clip to. It would also be nice to include a USB cable and/or serial null modem cable (due to the configuration of the instrument’s RS-232 port) and/or a Centronics 36-pin connector for the handler interface (as these are getting hard to find). However, considering the price and the nature of the instrument – it’s quite likely that users would end up building their own test fixtures to meet their application-specific needs.

Standalone User Experience

As a piece of bench-top test equipment, there’s a good chance that you might be using it “face-to-face”. I try to find out how easy is the BA6010 to use in this interactive scenario, what is it capable of and what are its limitations. As battery analysers are not common pieces of equipment, readers can think of this battery analyser as a specialised type of LCR meter that has its output terminals configured for kelvin operation for optimising small-resistance measurement, in an isolated manner so that it can measure in the presence of DC voltages, with a fixed 1khz operation frequency and a limited resistance range up to 3.5kΩ; all mashed together with a voltmeter as well. The unit also behaves a little more like an LCR meter, providing other modes of measurement (other than R-V) so as to enable it to measure capacitances and inductances within a limited range of values.

The supplied documentation with the BA6010 leaves something to be desired, as it is rather light on details in some cases and in others, contains typographical errors, confusing explanations, incorrectly labelled diagrams, inconsistent formatting and other subtle errors. Despite this, the information supplied is sufficient to get started.

Using the BA6010 is no more difficult than using most modern LCD and soft-button enabled multimeters and its large, bright, 4.3” 480x272 colour LCD screen with matte anti-glare finish is a great asset. Menu navigation is done through a mixture of soft-buttons, dedicated buttons and a directional pad, which is relatively intuitive and easy to master. Readings are displayed in a crisp, easy-to-read font, at a large size. While the LCD screen is in colour, the interface only makes limited use of the colour capability with mostly solid colour regions on the screen and white text throughout. The use of all caps text through most of the interface, along with unusual abbreviations does make the interface a little less user friendly.

The unit offers an array of measurement modes which include R, R-V, V, R-Q, L-Q, L-R, R-X, C-D, Z-θd, Z-θr and R-C. In the measurement display, it behaves similar to a multimeter, displaying measurement values and measurement parameters. In the Bin mode, it categorises the tested sample based on the measured value. In the Trace mode, a rudimentary graph of the measurement can be built up over time. Finally, in the Statistics mode, statistics on a number of readings can be computed within the instrument.

In my experience, I spent most of my time operating within the Measurement mode where it performed as expected. The Trace mode seems to be a good use of the LCD screen capabilities of the unit, but unfortunately, its implementation is somewhat basic requiring scales to be pre-set prior to measurement with no option to rescale or auto-scale. The X-axis is also fixed in scale, resulting in tedious sample-by-sample cursoring to scroll the graph along. In both Trace and Statistics modes, with sufficient samples, the screen does display visual corruption in the status line, suggesting a lack of polish in the firmware.

Instrument settings can be saved to internal memory and the onboard USB host port allows for connection of external USB flash disks for transferring settings, storing settings, logging data to .CSV files and taking screenshot data. In my experience, .CSV logging exhibited periodic pauses in data collection while flushing data to disk and occasionally, zero-byte screenshots were experienced on freshly formatted USB devices. It is also noted in the manual that devices with too many files stored may not be used with the BA6010 – in my case, I observed the instrument locking up once the device was attached.

The supplied test probes are well designed, featuring flexible ribbed gold contacts which hold onto battery terminals while making solid contact. The pre-arranged connections allow for quick, error-free connections to the analyser, with the analyser’s inbuilt nulling features further improving measurement accuracy. The large size of the probes, however, make measurements on small cylindrical cells difficult – a set of pogo-pin style probes might be a better option, but it is likely that most users will need to develop a solution specific to their needs.

The BA6010 is quite welcome on my bench as it’s quiet - keypad beeps can be disabled, leaving just the clicking of relays used to change measurement range. The one concern I had was with regards to its 220V rating. Despite being in a “240V” country, during many hours of use, I did not observe any failure or significantly unexpected behaviour from the BA6010. While being “out-of-spec” with regards to input voltage could theoretically reduce the instrument’s lifetime and affect its accuracy, in my RoadTest experience, it seems that this was not a problem.

PC-Connected Remote Operation

While the BA6010 can be used interactively with its large LCD and front panel buttons for spot measurements, the unit seems more suited to remote operation as part of a larger automated testing system especially with its higher reading rate modes.

The BA6010 is capable of PC-connected remote control through RS-232 (default) supporting a number of fixed baud rates from 9600bps to 115200bps, USB-CDC and USB-TMC modes. B&K Precision provide a programming manual which is comprehensive in covering the commands supported, with only minor typographical errors which I have reported for correction. The downside is that there are no instrument drivers provided (e.g. for LabVIEW) which might make integration easier for some users. That being said, the number of commands supported is fairly limited but complete, so it’s not a big issue to refer to the programming manual. The only exception seems to be support for returning the raw 1khz AC voltage and current measurements (Vm/Im) which are displayed on the screen.

While working with the device, there are some potential pitfalls to be aware of – one of which is that the device does return an extra useless field with FETC? commands (as noted in the manual). Another is that out-of-range readings which display with hyphens on the screen actually return numeric values over SCPI, but these are not directly related to the actual quantity measured – so seeing anywhere from >3.5kΩ to 12kΩ returned over SCPI indicates “out of range”.

With the BA6010 working in combination with the B&K Model 8600, I was able to perform AC internal resistance measurements to characterise the internal resistance behaviour of a sample of Alkaline, Ni-MH, lead-acid and Li-Ion cells over a full discharge. I was also able to perform AC and DC internal resistance measurements with the two units, confirming that the readings often differ but are both of value for different reasons.

The BA6010 was also successfully used on its own as a quick screening tool to identify the status of a box of random cells, as well as to determine the spread in parameters seen on a box of fresh cells. The BA6010’s 1kHz AC impedance test mode shows its strengths in being fast to screen cells, capable of being used simultaneously with a load on the battery, does not deplete the cells under test and the 60V range is highly appropriate for individual cells and small batteries alike.

The experiments also showed that for accurate results, it is imperative that users build their own test jigs to ensure consistent contact area, contact geometry and contact pressure to cells/terminals. Furthermore, to actually better understand what impedances are acceptable and which represent compromised cells, aside from using generalised “threshold” values, it can be necessary to characterise your cells to understand the impedance behaviour of a representative set of cells throughout their lifetime.

In my testing, I was able to able to automate testing and collect data continuously and also manually using pyvisa. The remote interface worked reliably to capture the data, although I did encounter some transient issues with one particular computer and combining other-vendor test equipment into the set-up that would cause “input protocol violations” to be reported. Adding an instrument_query_delay of 0.1s helped improve the situation which would only occur sporadically over the course of hours. Once the other vendor equipment was disconnected, no such errors occurred even with the delay removed while the other vendor equipment worked flawlessly throughout. I suspect this may be specific to the USB controller in my main desktop machine but I thought it was worth mentioning in case someone else encounters this.

I also encountered a situation where during auto-ranging measurements, the BA6010 was nearly continuously clicking its relays and changing ranges. It seems that very “dead” SLA gel cells can have such a high resistance and capacitance that the injected test current causes the battery to change its voltage or impedance so much that the range change (with a change in injected test current) leads to a jump in readings that causes the BA6010 to “hunt” through its ranges with the unstable reading. This doesn’t seem to be a design issue as such – more an interaction between the DUT and the measurement equipment.

Handler Interface and Binning

Aside from the computer-connected interfaces, the BA6010 is also capable of remote-control operation without involving a computer. This is achieved through the handler interface, which is intended to connect to an automated cell handling equipment, providing and receiving logic signals to control its operation.

The handler interface uses the rather “obsolete” Centronics-style 36-pin connector, which is difficult to obtain from most component suppliers. The documentation provided is also lacking many key details which are necessary to safely use the port with other equipment. This is not helped by some inconsistencies in naming of signals and ambiguous language. Likewise, the external trigger BNC port is also not well documented. Despite contacting B&K Precision Technical Support, only a limited amount of information was provided and it proved easier to just discover some of the relevant information through testing.

I was able to develop my own adapter through salvaging a connector from an old parallel-port printer cable. With this, I was able to verify the pin-out which more explicitly details the behaviour of the handler pins. There were some minor inconsistencies with the description provided by the manual, however, it was possible (in the end) to work successfully with the handler interface. Unfortunately, there still remains some details with timing and absolute voltage levels which I did not determine, which would be good to see in the documentation. Given the 25-unique-signals available, it would probably have been a better choice to use a DB-25 connector which still remain somewhat more widely available.

The binning feature allows for the analyser to categorise a given battery based on its readings. Binning is available for both primary measurements (COMP_A) and secondary measurements (COMP_B) in both absolute modes and relative modes. The binning process is of value in manufacturing quality control processes, where use with the handler interface with external trigger would allow for automated testing and sorting of batteries. A trial of the binning feature and handler interface output was successfully undertaken with some fresh AA alkaline batteries, allowing us to examine the behaviour of the bin output lines.

Instrument Performance Testing

The interesting part of reviewing an instrument is to actually test the instrument against the datasheet to understand how this one particular unit performs and determine how well it holds to the claimed specifications. As I now have a sizeable collection of test equipment, I felt it was only responsible to put it through a gauntlet of tests.

Putting the BA6010 through its paces, I was able to verify that my particular sample did seem to meet the voltage reading accuracy specifications, although with some discontinuities in the result and getting a little close to the limit especially towards the middle of the 60V range. The resistance reading accuracy as compared with a 4-digit handheld LCR meter showed a high level of concordance, suggesting to me that the BA6010’s resistance accuracy is quite good and potentially better than stated when testing simple resistors.

When measuring complex impedances, the accuracy depends on the reading and dissipation factor. While the manual was slightly confusing about this, I’ve attempted to distill it down into an Excel workbook along with a graph which shows that, in the slow mode for the majority of the range of values, error below 1.8% is achievable. Whether this is actually the case, I was not able to confirm.

The BA6010 seems to put out up to 2V peak-to-peak into a 10x oscilloscope probe and a maximum current of 100mA according to the datasheet, with voltage and current dependent on the measurement range and impedance connected. These levels should not be hazardous to humans, batteries or the gold-plating on the clips, which is good to know.

Standby power consumption for the instrument was tested to be 0.73595W, below the 1W limit set by the EU and quite a decent result. Active power consumption was tested to be approximately 10.5W, increasing slightly over time. Connected with this was the warm-up behaviour, which showed that voltage drifts of up to 2.4mV over six hours, with most of the movement completed within the first two hours and fully stabilising only after close to five hours. The resistance drifted less and was more stable overall, however, it seems that about one-and-a-half hours is needed to stabilise the resistance value.

Testing the measurement rates show that the datasheet claimed reading rates are in the best-case scenario of using the meter to measure voltage alone. Even then, the resulting read rates fall slightly short of the claimed 50Hz maximum in fast mode, reaching 47.6Hz in my tests. In R mode with a fixed range, the reading rate was around half of this. In R-V mode (as you might reasonably expect to use) with auto ranging enabled, I achieved 11.4Hz in fast mode, 3.7Hz in medium mode and 2.1Hz in slow mode which is quite different from what the datasheet might have you believe.

Conclusion

The B&K Precision BA6010 Battery Analyser is a highly attractive product for those who want a 1kHz AC impedance-based benchtop battery analyser. It offers outstanding specifications for the price, easily being half the price of the next comparable product from a big name. When compared even to its “Chinese” cousins, it offers a competitive price and specification without the risk that comes from buying from less reputable small-companies overseas. Being bundled with a pair of Kelvin clips, it is ready to begin testing right-out-of-the-box. In spite of its 220V rating, it satisfactorily operated in a 240V (nominal) country.

The BA6010 offers a wide variety of reading modes including R, R-V, V, R-Q, L-Q, L-R, R-X, C-D, Z-θd, Z-θr and R-C. The large 4.3” matte-finish colour LCD screen is surprisingly glare resistant and bright, being sharp and easy to read. The mixture of soft-button and dedicated keypad makes navigating the menus rather intuitive and easy to master. The unit is also practically silent once the keypad beeps are turned off, with the exception of relay clicks during range changing. The unit’s ability to perform CSV data, instrument settings, GIF screenshot saves to USB; binning, trace display and statistics can be of additional value.

Unfortunately, it seems the firmware does lack a little polish, with occasional graphical glitches, limitations in the scaling of the trace display mode, stalls in .CSV data recording, 0-byte screenshot saves and lock-ups due to USB drives with too many files. The supplied clips were suitable for use with batteries with terminals, however, for cylindrical batteries, another probe (e.g. pogo pin style) may be more suitable.

The provision of USB-TMC, USB-CDC and serial connectivity with a SCPI-based command-set increases the flexibility of the BA6010, allowing for it to be remotely controlled by a PC. In practice, the remote-control capabilities worked well based upon the data within the programming manual, although the choice of RS-232 connector and wiring was a little unusual, requiring a null-modem cable for connection. Unfortunately, B&K Precision do not offer any instrument drivers for the BA6010, thus reference to the programming manual is necessary to implement remote-control.

Additionally, a “handler” interface is provided for interfacing with other devices through logic-level inputs and outputs. This interface was poorly documented, requiring a moderate amount of effort in experimentation to get operational. While the information I’ve garnered is somewhat incomplete, it is more than what is provided by the manuals.

But an instrument is only as good as its performance – to this end, I have tried to characterise the instruments’ performance using an array of tests and other instruments. Within my limits of determination, it was found that the voltage and resistance accuracy seem to be compliant with the claimed accuracy. The only downside appears to be a relatively long warm-up time to a stable voltage reading and the fact the maximum reading rates can only be achieved in voltage-only mode.

While the instrument itself is quite solid, I unfortunately cannot overlook the fact that the documentation was somewhat lacking in detail and polish, containing a number of inconsistencies, grammatical and typographical errors. During the course of the RoadTest, I attempted to contact B&K Precision about a number of issues including the incorrect calibration certificate, specifications which had some inconsistencies with regards to temperature range, confusing explanations of measurement error within the manual which could use some clarification, data about the Handler interface which lacks key information (e.g. inputs or outputs, current/voltage ratings), commands for retrieving monitor measurement data (Vm/Im) which it seems to be lacking, a one-off voltage reading issue where readings were offset by 0.3V and a problem with occasional bus drop-outs under constant reading (which I now think is a compatibility issue with other vendor equipment and took a lot of experimentation to determine).

Unfortunately, despite making it clear that I was a RoadTester, responses from B&K Precision were completely absent at first until contacted by rscasny, followed by some sparse responses which only addressed one or two points but was otherwise unsatisfactory in terms of addressing the bulk of the enquiries. The latest communication had them “looking at the issue next week” over two weeks ago despite informing them that the review would be published within the next few weeks. Because of my frustration with the long turnaround, some of the discovered deficiencies have not been reported to the manufacturer to avoid further overwhelming them. As a result, I have to conclude that B&K Precision’s technical support for this product could be better.

In spite of this, the unit itself is still worthy of praise solely on the price to performance ratio and the fact there seems to be no major issues with functionality.

Don’t forget to read the “in depth” blog postings for more details. To find out what I’m up to (when I have the time to write, which is not often), feel free to visit my personal blog at https://goughlui.com.